The present invention relates to a solar ray collecting device, particularly a solar ray collecting device which can be preferably used at a place near the North Pole or South Pole.
It has been already proposed that a solar ray is focused by a lens, etc. and guided into an optical conductor cable, and further guided to an optional desired place for instance, the place to be illuminated for the purpose of illuminating the place. On that occasion, in order to effectively guide the solar ray into the optical conductor cable, the direction of the sun is detected by a solar ray direction sensor, etc. and the surface of the lens is so controlled as to always face towards the sun. One of such methods is to focus the solar ray by means of the Fresnel lens of about 40 cm diameter to guide the solar ray focussed by the lens into the light conductor having an edge surface of about 10 mm diameter arranged at the focus position of the lens, and to transmit the solar ray guided into the light conductor in such a manner through the light conductor to the optional desired position in order to use the solar ray for illumination or other purposes, for instance, as the light source for cultivating the plants in a room or an underground room, the light source for nurturing plants on the bottom of the sea, or the light source for culturing chlorella, etc. However, according to such method, the focal distance of the lens turns out to be longer, for instance, about 40 cm, and therefore the device becomes large-scaled or voluminous. And furthter, the light collecting energy per lens increases so that highly heat-proof material needs to be used as the member placed near to the focus position of the lens, and the operator may probably be in danger of suffering from burning the operator's hands, etc. at the focus position when the operator performs adjustment work for positioning the edge surface of the light conductor onto the focus position of the lens, and so on. According to the method, a large number of small lenses having a diameter of about 4 cm is used, and the edge surface of the optical fiber of 1 through 2 mm diameter is arranged at the focus position of each lens. The light collected by each lens is guided into the respective optical fibers, and the lights delivered from the respective optical fibers are guided into the optical conductor having a large diameter, for instance a diameter of 10 through 30 mm and transmitted to the optional desired position through the light conductor.
According to this method mentioned above, the focal distance of the lens turns out to be small, for instance, about 4 cm. Therefore, it may be possible to realize the device manufactured in a small-scaled and thin style. On the contrary, since a large number of lenses in used, it may be troublesome to position the light-receiving edge surface of the optical fiber onto the focus of each lens and perform its maintenance work.
The afore-mentioned solar ray collecting devices are constructed for possible widespread use on earth. Therefore the device needs a globular capsule and a gathered lens-assembly is constructed so as to form the outer circumferential surface approximately in the shape of a circle entirely corresponding to the shape of the capsule. However, considering that the afore-mentioned solar ray collecting device is used only at predetermined locations on earth, it may be possible to construct the device more effectively depending on the location. For instance, considering that the device is used at a place near the North Pole or South Pole, the sun moves along in an approximate horizontal, circular line from the east to the south, the west, and the north, so that the movement of the sun hardly shows the height variation along with a direction from the south to the north. Therefore, the capsule does not need to be formed in the shape of a globe. Furthermore, even though the surface of the capsule is perpendicular to the light progressing along a horizontal direction, the solar ray is not reflected on the surface of the capsule but it can be guided into the capsule.